Comparison between the color distribution of 1G stars in NGC 5272, NGC 6637, and NGC 6723. Top panels: ChMs of NGC 5272 (a1), NGC 6637 (a2), and NGC 6723 (a3) where the 1G stars are colored red. Middle panels: zoomed-in image of the ChMs shown in the top panels for 1G stars of NGC 5272 (b1), NGC 6637 (b2), and NGC 6723 (b3). Here, the Δ_{F275W, F814W} pseudo-color is normalized to the width of the 1G sequence. Bottom panels: cumulative (c) and kernel-density (d) distributions of the ${\mathrm{\Delta }}_{F275W,F814W}^N$ pseudo-color for 1G stars of NGC 5272 (dark blue), NGC 6637 (purple), and NGC 6723 (orange).